Other mistake: In the scene where Marnie's mother is in the Supermarket paying for her groceries and complaining about Marnie never calling. To pay, she swipes her debit card but has it turned the wrong way with the black magnetic strip up. She then enters her pin number and gets her receipt. With the strip up, the machine would have showed an error message and she would have had to slide her card again. (00:15:35)
Marnie Piper: My resident advisor's a genie?
Aneesa: The first to be accepted to Witch University. My parents are very proud.